THE LIVER 231 
infection with the necrosis bacillus, emanating from 
nearby infectious foci, or via the normal passageways 
from the intestine. Massive areas of degeneration may 
form by the coalescing of numerous foci, in any septi- 
cemic disease. 
Abscess. 
In man, amoebae, flukes, cestodes and biliary tract infec- 
tion are the commonest causes of purulent collections 
within the liver. In the lower mammals parasites play 
practically a solitary role at least as the major influence 
in localizing the collection, bacteria from the intestine 
doing the rest. We have one case of massive abscess in 
a porcupine suffering with septic pneumonia, the sup- 
puration in the liver being due to the colon bacillus, the 
general septicemia probably being from distemper. 
Monkeys have shown more abscesses than any other 
order, three being observed. One was due to infestation 
with trichocephalus which had apparently penetrated 
from the colonic wall into the liver through adhesions 
formed between these two structures. Another seems 
certainly amoebic but these protozoa could not be found, 
while the third followed an ulcerative enterocolitis of 
unknown cause. Two cats were seen with parasitic 
abscesses ; one harbored Distoma or Clonorchis sinensis, 
the other a nematode of ascaris type. 
The topographic distribution of these six hepatic 
abscesses was interesting. The position of the abscess is 
not mentioned in one case but of the remaining five three 
were entirely in the right lobe, one had the major lesion on 
the right side and smaller separate abscesses spread over 
the organ, and one with about equal distribution in all 
lobes. All three confined to the right side were solitary. 
Abscesses of considerable size are not met with in the 
bird as in the mammal perhaps because the former does 
not form real pus, necroses developing instead. 
